Alcohol & Drugs Flashcards

Question

Delirium Tremens - Symptoms

Answer 1

Occurs in 3-5%. Usually occurs 3-4 days following alcohol cessation. Mortality rate is 10-20% if untreated. Main symptoms: Clouding of consciousness / confusion Vivid hallucinations, particularly visual and tactile Marked tremor Other symptoms = Autonomic hyperactivity, tachycardia, HTN, sweating, fever, paranoid delusions, agitation, insomnia

Answer 2

- abnormal liver function - old age - severity of withdrawal symptoms - concurrent medical illness - heavy alcohol use / severe dependence - self-detox (no medical input) - previous history of DT - low potassium - low magnesium - thiamine deficiency

Answer 3

Alcohol enhances the effect of GABA on GABA-A, decreasing overall brain excitability. Chronic exposure results in a compensatory decrease of GABA-A neuroreceptor response to GABA. As a result when people stop drinking their brains become very excitable. For this reason benzodiazepines are the main stay of treatment. Diazepam first-line (lorazepam, oxazepam or temazepam in liver disease). Thiamine to prevent Wernicke’s encephalopathy. Should be parenteral if they are in a hospital setting or if Wernicke’s is suspected. Give for 5 days and then oral treatment for as long as necessary (where diet inadequate or drinking is resumed). If an antipsychotic is required, haloperidol is the treatment of choice. Long-acting benzodiazepines are effective in preventing withdrawal seizures and should be used as prophylaxis in those with a history of this.

Answer 4

Characterised by the triad of global confusion, ophthalmoplegia, and ataxia. Other symptoms = hypothermia, hypotension, memory disturbance, coma.

Answer 5

Results from prolonged thiamine deficiency, which can occur in: - Alcohol dependence - Anorexia nervosa - Following gastric surgery - Malignancy - AIDS - Hyperemesis gravidarum - Prolonged total parenteral nutrition

Answer 6

The lesions occur in a symmetrical distribution in structures surrounding the third ventricle, aqueduct, and fourth ventricle. The mammillary bodies are involved in up to 80% of cases, and atrophy of these structures is specific for Wernicke's encephalopathy. Pathological features include neuronal loss and demyelination in periventricular grey matter, and haemorrhage and small vessel proliferation in the mamillary bodies, thalamus, cerebellar vermis, and pons.

Answer 7

IV thiamine (vitamin B1), as oral forms of B1 are poorly absorbed. Of those untreated, 80% go on to develop Korsakoff's syndrome . IV glucose should be avoided when thiamine deficiency is suspected as it can precipitate or exacerbate Wernicke's. With treatment, ophthalmoplegia and confusion usually resolve within days but the ataxia, neuropathy, and nystagmus may be prolonged or permanent.

Answer 8

Chronic syndrome characterised by impaired recent memory and anterograde memory in an alert and responsive patient. It is caused by prolonged thiamine (vitamin B1) deficiency and follows Wernicke's encephalopathy. Other features include lack of insight, apathy, and confabulation. Intelligence on the WAIS is preserved. Episodic memory is characteristically severely affected. Semantic memory is variably affected. Implicit aspects of memory, including the response to priming and perceptuomotor (procedural) memory are preserved. Immediate memory tested with the digit span is normal, but information can be retained for at most a few minutes.

Answer 9

Thiamine is used in the brain to metabolise glucose. When deficient, a build-up of glucose occurs, which is toxic and causes neuronal loss. The main areas affected in Korsakoff's syndrome are the mamillary bodies.

Answer 10

Withdrawal symptoms may develop upon abrupt discontinuation of opioids, after as little as 5 days of regular and uninterrupted opioid use. For short-acting opioids (eg, heroin), acute withdrawal symptoms usually begin 4-6 hours after the last dose, peak in 32-72 hours, and diminish over the next 3 to 5 days. For longer-acting opioids (eg, methadone) acute symptoms occur within 30 to 72 hours after last dose (although anxiety may occur before this), peak at day 4-6, and resolve over the next 10 days or so.

Answer 11

The opioid receptors (µ, k, and δ) are G protein-coupled receptors. The key opioid receptor subtype is µ, which mediates euphoria, as well as respiratory depression, and is the main target for opioids. The k receptor is involved in mood regulation. The delta (δ) receptor is involved in anxiolysis. All three are involved in analgesia.

Answer 12

Dopaminergic cells within the VTA (ventral tegmental area) produce dopamine, which is released into the nucleus accumbens upon stimulation of μ receptors, producing the euphoria and reward that helps drive repeated use. With repeat opioid exposure, μ receptors in the ventral tegmental area neurons become less responsive to opioid binding and less dopamine is released. This causes dysphoria and depressed mood and contributes to drug craving.

Answer 13

Full agonist targeting µ receptors (some action against k and δ) Half-life = 15-22 hr. Can cause respiratory depression. Can effect QTc. Used in pregnancy.

Answer 14

Partial agonist targeting µ receptors (also a partial k agonist or functional antagonist (possibly with antidepressant effects), and a weak δ antagonist. Half-life = 24-42 hr (PO). Very high affinity for µ receptor (5 times that of morphine). Metabolised by CYP3A4/5. Safer than methadone in terms of resp depression, less euphoria. Can precipitate withdrawal.

Answer 15

Antagonist targeting all opioid receptors Half-life = 30-120 minutes. Active within minutes. Associated with noncardiogenic pulmonary oedema in up to 3.5% of cases.

Answer 16

Alpha-2 adrenergic agonists. Used to help opioid withdrawal symptoms (those associated with the NA system, including sweating, shivering, and runny nose and eyes). Lofexidine has less of an hypotensive effect than clonidine.

Answer 17

Locus coeruleus (in pons) has a high density of noradrenergic neurons that possess μ-opioid receptors. It is involved in the stimulation of wakefulness, blood pressure, and breathing, and in overall general alertness. Exposure to opioids results in heightened neuronal activity in these cells. If opioids are not present to suppress the increased activity, increased amounts of NA are released and withdrawal symptoms appear (eg, jitters, anxiety, muscle cramps, diarrhoea).

Answer 18

Phencyclidine (angel dust). Hallucinogenic. Leads to illusion of euphoria, omnipotence, superhuman strength, and social and sexual prowess. NMDA receptor antagonist (like ketamine) with dissociative properties. Formerly used for anaesthesia and analgesia without triggering cardiorespiratory depression. Intoxication = violent behavior, nystagmus, tachycardia, hypertension, anesthesia, analgesia. Intoxication is best managed with benzodiazepines along with supportive measures for breathing and circulation.